India-rubber spring



May 21, 1935.

A SPENCER INDIA RUBBER SPRING Filed Jun 24. 1932 2 Sheets-Sheet 1 May 21, 1935. A. SPENCER INDIA RUBBER SPRING Filed June 24, 1932 2 Sheets-Sheet 2 i/zaader- $19766) J r 1' [7 4 I zfnngy Patented May 21, 1935 UNITED STATES PATENT OFFICE Eng Application-June24, 1932, Serial No. 619,165

In Great Britain March 22, 1932 I Claims.

' This invention relates to india-rubber spring units and has more especial reference to units comprising a metal foundation or supporting plate and bars of india-rubber projecting from 5 the opposite sides thereof and united through perforations in the plate.

Hitherto india-rubber springs for bufiing and draft gear and for other purposes have comprised a plurality of such units assembled in series with intermediate separating plates, each supporting plate having rectangular or annular frames of iI'idia-rubber projecting from its opposite faces, and in copending application Ser. No. 360,293 applicant has proposed an outside bufiing spring encircling the coupler shank, the spring units mounting parallel bars thereby simplifying the moulds necessary for the manufacture of the units and also providing a spring assembly eminently suitable to its purpose of cushioningwhen bufling on curves.

Test and experiment have disclosed that when springs composed of bar type elements are 'subjected to compression there is a greater flow of material or a' larger degree of distortion transversely of the bars than in the length direction, and whereas such bars are usually assembled on their supporting plates in juxtaposed relation 0 with intervening spaces such that under'compression the bars become distorted and occupy said spaces ultimately bringing the side walls of adjacent bars into contact and thereby providing mutual support between the bars, it will be appreciated that theterminal or marginal bars and to a lesser degree the bars immediately juxtaposed thereto have their neutral axes displaced outwardly of the supporting plate when subjected to compression thereby adversely 40 affecting the stability of the spring and increasing the wear and tear thereon in use. 7

The present invention has for its main object to provide dispositions of spring elements obviating this disadvantage in which the elements of the spring are, to the maximum possible extent, brought into a condition of mutual support under compression.

According to the invention an indie-rubber spring unit comprises a metal plate and bars of 50 india-rubber projecting from the faces thereof and united by india-rubber "passing through perforations in the plate, the bars being disposed in juxtaposed relation with their major axes normal to or in quadrature with the adjacent edgeof the plate. Preferably, the arrangement is bufling impact whetherapplied longitudinally of the vehicle or at an inclination, as for instance.

such that nobars in the immediate vicinity of the plate edge are parallel thereto and a high degree of mutual support between the several bars of the spring is thereby obtained when the spring is subjected to compression.

Preferably also the bar elements employed have their central portions reduced in dimensions whereby under a predetermined compression the side walls become substantially parallel to each other and to the longitudinal axis of the 10 bar, the spacing between the bars being determined so that mutual contact occurs in this condition with maximum support between adjacent bars, this arrangement of spring element forming the subject-matter of co-pending applica- 15 tion, Serial No. 619,164.

Reference will now be had to the accompanying illustrative drawings which show by way of example dispositions of spring element according to the invention and in which,

Fig. 1 is a perspective view, and Fig. 2 an empiric illustration showing the improved deformation resulting from waisting the bar according toco-pending application, Serial No. 619,164. I

Fig. 3 is an elevation of a spring unit comprising a metal supporting plate having waisted bars of the form coveredgby the aforementioned copending application disposed according to the present invention, Fig. '4 showing a plurality of such units assembled on a draw rod with metal separating plates between adjacent units and adapted for use in cushioning either buff or draw stresses, the front portion being shown partly in section to clearly indicate the interior arrangement.

Fig. 5 is an elevational view similar to Fig. 3 showing an alternative disposition of bars, and Fig. 6 is also an elevational view having a general configuration similar to that shown in Fig. 3 but employing the usual form of bar type element, 40

Fig. 7 being an end elevation, partly in section V to show the junction between the bars projecting from the opposite sides of the metal plate.

Referring now to the drawings, but first more particularly to Figs. 1 and 2, the bar elements usually employed as elements for india-rubber spring units have their side walls located parallel to each other and to the longitudinal axis of the bar when in a condition of rest.

0n the her being subjected to compression the 60 relative expansion transversely of the bar greatly exceeds the corresponding expansion in the longitudinal direction thereof, the intermediate portion between the plain top andbottom surfaces exceeding, as is well understood, both in a longlfiplates comprising the foundation of the spring adjoining terminal ends so that the bulk of the distortion resulting from compression is forced to take place in a transverse direction, and, as aforementioned, this inherent asymmetry of a bar-type element possesses the disadvantage that when the bar elements are assembled'on a supporting plate, for instance as shown in Fig. 3, instead of the continuous mutual support between adjacent bars which would obtain should the side walls of the spring distort uniformly throughout the length of the bar, such mutual support is only provided at the central portions of the bars.

With the primary object of overcoming this disadvantage and of obtaining a construction of spring the elements whereof shall have mutual support on each side for the major portion of their length, the bar element according to the invention is shaped as indicated in Figs. 1 and 2, the centre portion bounded by the lines-represented at 4 and 5, being waisted or reduced so as to have a transverse width substantially less than the portions lying towards each end of the bar, the transverse dimensions whereof progressively increase towards each end.

Where rectangular bar elements are employed the major transverse dimension would be in the immediate vicinity of each end, although as it hasbeen found that, in use, rapid deterioration of the corner portions is caused by the high internal stress set up when the bar is distorted by compression, it is preferred to have the end faces of the bar of general semi-circular or semielliptical form as shown at 6 and I in Fig. 2, in which case the major transverse dimensions of the bar as indicated at 8 are located where the circular end faces 6 and 'I join the side walls.

When the bar elements of this form, 1. e. according to the aforementioned co-pending application Serial No. 619,164, are subjected to compression owing to the greater resistance to molecular flow in the longitudinal direction, the side walls of the bar become substantially parallel to each other as will be apparent from the dotted showing at 9 and I0.

Substantial operating advantages accrue from the use of bar-typeelements having their centre portions of reduced dimensions while the durability and stability of the assembled springs under compression is greatly enhanced.

For instance, referring now more particularly to Figs. 3' and 4, l2 indicates metal supporting unitswhich are assembled in series-with metal separating plates I3, on a draw rod l4, pivoted to the rear of a coupler shank l5 and bfiween followers l6 and I1 in the draft gear of a railway vehicle.

The bar elements l8 of india-rubber project from each face of the metal supporting plate l2, the coincident bars on opposite sides of the plate being united by indie-rubber passing through perforations in the plates as shown at I9.

' An example of the quadrated disposition providing maximum stability is represented in Fig. 3 where, as will readily be seen, the bars are disposed with their major axes normal to the adjoining edges of the supporting plate |2..

Each of the parallel series of bars 20 has its longitudinal axis disposed normal or at right angles to the adjacent plate edge 2], a facsimile of the parallel series 20 being disposed at the other side of the plate adjacent the other edge 22 and being indicated by the reference 23. Intermediate these series and adjoining the top edge 24 and the bottom edge 25 respectively of the plate [2 are two further parallel series of springs 26 and 21 having their longitudinal axes vertical, that is at right angles to their adjacent plate edges.

Each of thebar elements I8, 20, 23, 26 and 21 is of the waisted section shown in Fig. 2 and has' assures a high degree of stability for the reasons hereafter explained.

The invention is not confined in its effective application to the preferred forms of spring elements shown in the preceding figures. For instance, Fig. 5 illustrates a unit comprising a supporting plate 30 having a central aperture 3| and having projecting from each face india-rubber bar elements of standard form.

The'series of parallel bars indicated at 32 are disposed normal to the side edge 33 and the series 34 are similarly disposed in relation to the side edge 35. Intermediate the series of horizontally running spring elements 32 and 34 are elements disposed with their longitudinal axes vertical or at right angles to the top and bottom edges 36 and, 31 of the plate 30.

The vertically disposed elements comprise short bars 38 and 39 disposed above and below the centre aperture 3| respectively and bars 40 and 4| on each side thereof extending substantially for the full vertical dimension of the plate 30.

The end walls of the bars are preferably of semicircular form, although the ends of the short bars 38 may, as illustrated at 42 and 43, be radiused around the central aperture 3|, it being understood that the bars 38 and 39 respectively represent alternative forms of bar suitable for use adjacent the central aperture.

The supporting plate 30 has its corner bevelled at 44 and the bars 45 in the immediate vicinity of such bevelled corners are for convenience disposed at right angles to the side edges 33 and 35 respectively.

It is probably unnecessary to emphasize the bilateral and vertical stability of the spring units having elements disposed in quadrated relation over their surfaces, although it may be mentioned that any lateral instability of the vertically disposed elements 38, 39, 49 and 4| resulting from their transverse resiliency is substantially counteracted by the lateral stability resident in the horizontal bars 32, 33, and 34 whose major axes are disposed in the direction of such lateral movement and vice versa.

Any number of units comprising the supporting plates 30 having bars projecting from their opsigned for disposition within a quasi-rectangular casing, for instance as is usually employed with outside buffing gear.

' The embodiment of unit shown in Figs. 6 and 7 is similar in general configuration to that shown in Fig. 3 and already described, except that standard bar elements are utilized and the supporting plate 50 in addition to its centralaperture is provided with symmetrically placed apertures 52 for the receipt of retaining or guide members. The disposition of the spring elements is modifled to accommodate such apertures 52, although the principle of the invention is followed, the two series of horizontal bars 53 and 54 respectively being disposed adjacent the vertical edges 55 and 56 of the plate and two vertical series 51 and 58 respectively being located adjacent the upper and lower horizontal edges 59 and 60 of the plate.

The elements project from both faces of the plate as shown more clearly from Fig. '7 and are of general square section, although for convenience of manufacture they taper slightly to their outer faces, the coincident elements on opposite sides of the plates being joined by india-rubber at 6| which passes through perforations provided for the purpose in the body of the plate asis usual with springs of this character.

Where desirable or convenient the india-rubber bar elements disposed in quadrature according to the invention may be associated with annular or. frame-type elements should space permit.

The invention also comprehends an improved and more economical method of manufacturing bar-type spring units, wherein the usual perforations in the metal supporting plates are replaced by elongated slots and integral bar elements positioned in said slots project at opposite faces of the plates.

The improved method consists in inserting through the said elongated slots extruded bars of rubber so that a portion of each bar projects at the opposite faces of the plate, and thereafter vulcanizing the bars in moulds the form of which produces an interlocking engagement between the bars and the supporting plate.

For instance, referring to Fig. 3, the dotted lines 62 represent elongatedslots in the plate 24 and bars of this form -would be cut from a continuous length of spewed rod, the depth of which would be somewhat more thanthe overall thickness of the finished unit, such bars being positioned in the plate slots 62 prior to vulcanization. The moulds or matrices are of a shape that will give the bars the required form, e. g. the waisted form illustrated in this figure, or the more usual cylindrical form, overlying the margins of the slots by about whereby when vulcanized the bars are securely interlocked to the supporting plate and a durable spring unit obtained.

The improved process is especially suitable for the. manufacture of bar type spring units, since while the union of the calender-ed rubber from which annular or frame type springs are usually manufactured through the multitudinous perforations can be performed satisfactorily, and moreat opposite faces, any likelihood of displacement is removed.

What I claim is:

1. An india-rubber spring unit comprising a generally rectangular plate, bars of India rubber projecting from the faces of said plate, a portion of said bars being arranged in two spaced groups with one group adjacent each of opposite edges of the plate, and a plurality of bars on said plate intermediate planes passing through inner end portions of bars of said spaced groups, the bars of each of the spaced groups having their major axes normal to the respective adjacent edge of the plate and the major axes of the plurality of intermediate bars being normal to the major axes of the bars of the spaced groups.

2. An india-rubber spring unit comprising a generally rectangular plate having perforations therein, bars of india rubber projecting from the faces of said plate with bars on opposite faces of the plate being united by india rubber passing through the perforations, a portion of said bars being arranged in two spaced groups with one group adjacent each of opposite edges of the plate, and a plurality of bars on said plate intermediate planes passing through inner end portions of bars of said spaced groups, the bars of each group having their major axes normal to the respective adjacent edge of the plate and the major axes of the plurality of intermediate bars being normal to the major axes of the bars of the spaced groups, the intermediate bars and the bars of the groups being so spaced apart that under the deformation resulting from a predetermined compression the side walls of adjacent bars come into mutual contact.

3. An india-rubber spring unit comprising a generally rectangular rigid plate having perforations therein, relatively short bars of india rubber projecting from the faces of the plate with bars on opposite faces of the plate being united by india rubber passing through the perforations, a portion of -said bars .being arranged in two spaced groups with one group adjacent each of the vertical edges of the plate, the bars of said groups having their major axes normal to said vertical "edges, and a, plurality of bars on said plate intermediate planes passing through inner end portions of bars of said spaced groups and arranged in the central portion of the plate with their major axes normal to the major axes of the bars of the spaced groups, the bars 'of each group and the intermediate bars being so spaced apart that under the deformation resulting from a predetermined compression the side walls of adjacent bars of the respective groups and'of the intermediate bars come into mutual contact.

4. An india-rubber spring including a plurality of aligned units with intermediate separating plates, e'ach unit comprising a generally rectangular plate having perforations therein and bars of india rubber projecting from the faces of said plate, a portion of said bars being arranged in two spaced groups with one group adjacent each of opposite edges of the plate, a plurality of-bars on said plate intermediate planes passing through inner end portions of bars of said spaced groups, the bars of each group having their major axes normal to the respective adjacent edge of the plate and the major axes of the plurality of intermediate bars being normal to the major axes of the bars of the spaced groups.

5. An india-rubber spring including a plurality of aligned units withintermediate rigid separating plates, each unit comprising a rigid plate of generally rectangular form having perforations therein, relatively short bars of india rubber projecting from the faces of said plate with bars on opposite faces being united by india rubber passing through the perforations, a portion of said bars being arranged in two spaced groups with one group adjacent each of the vertical edges of the plate and the bars of said groups having their major axes normal to the respective adjacent edges of the plate, and a plurality of groups on said plate intermediate planes passing through inner end portions of bars of said spaced groups and arranged substantially centrally of the plate and with their major axes being normal to the major axes of the bars of the spaced groups, the bars of the spaced group and the bars of the central portion of the plate being so spaced apart that under the deformation resulting from a predetermined compression the side walls of adjacent bars of, the respective groups and of the bars at the central portion of the plate come into mutual contact.

ALEXANDER SPENCER. 

